How did China's geography play a role in their ancient civilization?
This is an intelligent question, because one of the most important determining features of a people is geography. The geography of the land shapes people in profound ways. In a land as large as China, many things can be said, but a few features stand out.
First, the Yellow river enabled China to become a great empire. According to Chinese poets, the Yellow river is called "mother river" and has been viewed as the cradle of Chinese civilization. This is why many dynasties came to power around the Yellow River. For example, for the Shang (16th-11th century BC) dynasty to the Tang Dynasty (618-907), the Yellow River area was always a center of politics, economy, and culture.
Second, the many mountains and the deserts kept China from concerted Westerns influence for much of its history. To be sure the Silk Road helped to bride East and West, but these geographic features isolated China in a real way.